Draft:Linear description

Linear description, also named linear assessment or linear scoring system, is a common tool in animal breeding when assessing conformation traits in for example cattle, sheep or horses. The method was first implemented in dairy breeding in the 1970's, and is today a well-accepted method to provide comparable data within breed.[1]

In traditional evaluations, most traits are subjectively assessed in comparison to a breeding goal. The linear description was developed in order to assess traits in a more objective way, by describing the trait on a scale between two biological extremes (i.e. long-short, small-wide)[1]. Because a large amount of traits is described at the assessment, the method also gives a more detailed and uniform description of the individual.[2] The assessment scale normally has seven or nine values (i.e. 1-7, or A-I), and in comparison to traditional evaluation there is no value that are rated as "the best".

A trait need to fulfill four main factors in order to be included in a linear description[3]:

  • The trait need to have a clear definition
  • There must be some kind of dispersing within the trait
  • The trait must be repeatable, i.e. it must be possible to describe it several times at the same time and by the same judge
  • The trait must be reproducible, i.e. it must be able to be described in the same way but at a different time and by a different judge

References

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  1. ^ a b Duensing, J., Stock, K.F., Krieter, J. 2013. Implementation and prospects of linear profiling in the warmblood horse. Journal of Equine Veterinary Science 34, 360-368.
  2. ^ Koenen, E.P.C., Aldridge, L.I., Philipsson, J. 2004. An overview of breeding objectives for warmblood sport horses. Livestock Production Science 88, 77–84.
  3. ^ Verkerk, J. 2011. Linear scoring of horses – KWPN perspective. Interstallion workshop on linear profiling in the horse, 14-15 december 2011, Arlanda, Sverige. Tillgänglig: http://www.biw.kuleuven.be/GENLOG/livgen/research/interstallion/workshop_Arlanda2011/1_linear _scoring_KWPN%20Jacques%20Verkerk.pdf [2014-04-09]